DE102020210893B4 - Process for producing sealed adhesive tapes with curable adhesive compositions, sealed adhesive tape and use - Google Patents

Abstract

Method for producing sealed adhesive tapes (10) with curable adhesives (12), comprising the steps: a) producing or providing a curable adhesive (12), b) applying the curable adhesive (12) to the middle section of a coating liner (14), to obtain a partially coated coating liner (14) having a first and a second uncoated portion (16a, 16b) on opposite sides of the coated center portion,c) covering the partially coated coating liner (14) with a cover liner (18) to obtain a Layer arrangement (20), in which the covering liner (18) completely covers the coated central section of the coating liner (14) and at least partially covers the first and second uncoated sections (16a, 16b), andd) connecting the covering liner (18) to the coating liner ( 14) of the layer arrangement (18) uncoated in the area of the first and the second en section (16a, 16b), to obtain a sealed adhesive tape (10).

Description

The invention relates to a method for producing sealed adhesive tapes with curable adhesive compositions, a corresponding sealed adhesive tape and the use of a corresponding sealed adhesive tape for joining two elements. A roll of adhesive tape is also disclosed, comprising a corresponding rolled up sealed adhesive tape.

The subject matter of the invention is defined in the appended claims.

The joining of separate elements is one of the central processes in manufacturing technology. In addition to other methods, such as welding and soldering, bonding, i.e. joining using an adhesive, is of particular importance today. An alternative to the use of shapeless adhesives, which are applied from a tube, for example, are so-called adhesive tapes.

In particular, pressure-sensitive adhesive tapes are known from everyday use in which a pressure-sensitive adhesive mass that is permanently tacky and adhesive under normal ambient conditions ensures the adhesive effect. Corresponding pressure-sensitive adhesive tapes can be applied to a substrate by pressure and stick there, but can later be removed again more or less without leaving any residue.

In addition, however, a second type of adhesive tape is also of great importance, in particular for use in industrial manufacturing technology. In these adhesive tapes, a curable adhesive is used instead of a permanently tacky PSA.

Corresponding curable adhesives have not yet reached their maximum degree of crosslinking in the state envisaged for application and can be cured by external influences by initiating polymerization in the curable adhesive and thereby increasing the degree of crosslinking. The mechanical properties of the now cured adhesive composition change here, with the viscosity, the surface hardness and the strength increasing in particular.

Curable adhesives are known in the prior art and, from a chemical point of view, can have very different compositions. What these curable adhesives have in common is that the crosslinking reaction can be triggered by external influencing factors, for example by the supply of energy, in particular by temperature, plasma or radiation curing, and/or contact with a substance that promotes polymerization, as is the case, for example, with moisture-curing adhesives is. Corresponding adhesives are, for example, in DE 10 2015 222 028 A1 , EP 3 091 059 A1 , EP 3 126 402 B1 , EP 2 768 919 B1 , DE 10 2018 203 894 A1 , WO 2017 / 174 303 A1 and U.S. 4,661,542 A disclosed.

• A 5 bis 60 Gew.-Teile wenigstens einer Filmbildner-Komponente;
• B 40 bis 95 Gew.-Teile wenigstens einer Epoxid-Komponente;
• C 10 bis 500 Gew.-Teile wenigstens eines feuchtigkeitsaktivierbaren
• Härters;
• D optional 0,1 bis 15 Gew.-Teile wenigstens eines Stabilisators,
• sowie
• E optional 0,1 bis 200 Gew.-Teile wenigstens eines Zusatzstoffs,
• jeweils bezogen auf die feuchtigkeitshärtende Zusammensetzung,
• wobei sich die Gew.-Teile der Komponenten A und B zu 100 ergänzen und wobei die feuchtigkeitshärtende Zusammensetzung dadurch gekennzeichnet ist, dass der feuchtigkeitsaktivierbare Härter C zumindest ein geblocktes Amin umfasst oder daraus besteht.

DE 10 2016 207 075 A1 describes a pressure-sensitive adhesive tape containing or consisting of a moisture-curing composition containing or consisting of:

• A 5 to 60 parts by weight of at least one film former component;
• B 40 to 95 parts by weight of at least one epoxy component;
• C 10 to 500 parts by weight of at least one moisture-activatable
• hardener;
• D optionally 0.1 to 15 parts by weight of at least one stabilizer,
• such as
• E optionally 0.1 to 200 parts by weight of at least one additive,
• in each case based on the moisture-curing composition,
• where the parts by weight of components A and B add up to 100 and where the moisture-curing composition is characterized in that the moisture-activatable hardener C comprises or consists of at least one blocked amine.

EP 3 549 994 A1 relates to an adhesive composition containing a base polymer and a moisture-curable component, the base polymer not containing a functional group that reacts with the moisture-curable component,
the water content of the base polymer is 0.1% by weight or less after storage at 25°C and 50% relative humidity for 24 hours and
maintaining the moisture-curable component in the non-reacting state.

Of particular interest for practical use are those curable adhesives in which curing takes place at least partially automatically under ambient conditions and, for example, no complex thermal treatment is necessary. These curable adhesives include, for example, those that contain a photoinitiator and are accordingly curable by radiation, for example UV radiation, and adhesives that are moisture-curing, since the interaction with the environment in these systems is sufficient to initiate the polymerization reaction.

The advantage of radiation- and moisture-curing adhesives and corresponding adhesive tapes is that they can be used particularly easily in many cases, since curing can begin even under normal ambient conditions, or only relatively simple process steps are necessary to achieve adequate crosslinking .

However, corresponding adhesives which can be cured by moisture or electromagnetic radiation have considerable disadvantages from the point of view of production technology. This is due to the fact that in many cases the atmospheric humidity of the ambient air or daylight is already sufficient to initiate a crosslinking reaction, so that these adhesives have to be packaged in an airtight and/or radiation-tight manner in order to prevent unwanted curing.

These curable adhesives or corresponding adhesive tapes are already exposed to the effects of light and humidity during the production process, so that by the time the manufactured adhesive tapes are packaged in an airtight and radiation-tight manner, i.e. during the so-called open time, the curable adhesive has begun to cure can. Such premature partial curing of the curable adhesive is undesirable in terms of the performance and the reproducibility of the adhesive properties of the adhesive tape produced and is regularly perceived as a major disadvantage of corresponding systems.

This is due in particular to the fact that corresponding adhesive tapes in industrially relevant applications are usually produced as long strands and wound onto large rolls, so that it can take several hours between the start and end of the production of a wound adhesive tape. The quality of the curable adhesive deteriorates continuously until the moisture-tight and/or radiation-tight packaging of the rolls of adhesive tape produced. This limits the maximum production time that is available for the production of a corresponding roll of adhesive tape, which also implicitly limits the maximum length of the wound-up adhesive tape.

In addition, the susceptibility of the processed adhesive mass to external influencing factors such as moisture or radiation also means that there is a comparatively large number of rejects in the event of unintended downtimes of the production device, since the adhesive tape being produced can lose too much quality during the downtime of the device than it can still do would be for sale.

The problem described above not only applies to those curable adhesives that are moisture-curing and/or radiation-curing, but also applies to a wide range of other curable adhesives, for example adhesive tapes, in which a certain material moisture content is set to maintain the processing properties must, in which certain volatile solvents and/or monomers are present or contain components that can enter into an undesirable side reaction with atmospheric moisture. In all these cases, too long an open time during production regularly leads to an unacceptable loss of quality.

The problems in the production process described above also regularly continue in subsequent use with corresponding curable adhesive tapes. When the roll of adhesive tape sealed in a moisture-tight and/or radiation-tight manner is removed from the outer packaging in the final application, the unwanted hardening processes continue at least partially, as a result of which the quality of the adhesive tape also gradually decreases during use. Whenever the entire adhesive tape wound up on the adhesive tape roll is not processed promptly after the outer packaging has been opened it can happen that the lower windings are no longer suitable for the intended use after a corresponding open time.

This problem requires that the end users of the adhesive tapes, for example employees in production, are sensitized to this problem and can assess during use whether an adhesive tape with a corresponding curable adhesive composition is still suitable for use after a given open time. If this is not the case, under certain circumstances it may even happen that an adhesive tape is used to join a potentially critical composite, which is actually no longer suitable for this purpose because the open time is too long. This can cause significant economic damage and pose a security risk.

It was the object of the present invention to eliminate or at least alleviate the disadvantages of the prior art described above. In particular, it was an object of the present invention to specify a process for the production of adhesive tapes with curable adhesives in which the quality of the adhesive tape produced is improved, in particular by avoiding or at least reducing premature curing.

The adhesive tape produced should also be storable for a long time without separate outer packaging, without premature curing leading to irreparable damage to the adhesive tape or a deterioration in the adhesive properties.

A secondary object of the present invention was that the method to be specified should preferably contribute to preventing the curable adhesive composition from escaping unintentionally on the longitudinal sides of the adhesive tape to be produced, in order to minimize material losses and to achieve a visually appealing product as easily as possible. whose adhesive mass at the edges of the adhesive tape cannot come into unintentional contact with the environment and cause disruptive adhesions.

Ideally, the method to be specified should be associated with a comparatively small amount of equipment, with the use of a vacuum, a protective gas atmosphere and/or a darkroom and/or comparable precautions preferably being dispensed with.

With a view to later use, it was an object of the invention that the adhesive tape to be produced with curable adhesive composition can be prepared in a simple manner for use in the end application and that the use by the end user can be carried out particularly safely and with consistent quality, even if the use of the adhesive tape takes place over a longer period of time.

In this context, it was desirable that the method to be specified should not require the use of potentially hazardous chemical substances and ideally be able to be carried out largely on devices that are already available from the conventional methods for producing adhesive tapes.

The method to be specified should also reduce the waste of unusable adhesive tape that occurs when the production devices fail.

One requirement here was that the process to be specified should be usable for a wide range of curable adhesives, in particular for moisture-curing and/or radiation-curing adhesives and adhesives with volatile constituents, such as volatile monomers or moisture.

The process to be specified should be suitable for large production quantities and easy to integrate into existing production lines.

In the light of the above statements, it was also an object of the present invention to specify an adhesive tape with a curable adhesive which has high resistance to external influences immediately after production and in which premature, unwanted curing can be avoided or at least reduced.

Finally, it was an object of the present invention to specify a use of a corresponding adhesive tape for joining two elements.

The inventors of the present invention have now found that the objects described above can surprisingly be achieved if the curable adhesive is covered with a cover liner shortly after application to a coating liner and the two liners are then connected to one another on the sides of the curable adhesive applied , thereby creating a seal. In this way, an adhesive tape with a curable adhesive composition is obtained directly from the process according to the invention, which is sealed by the covering liner and its connection to the coating liner and is therefore shielded from environmental influences, for example light and/or atmospheric moisture.

By choosing a suitable covering and/or coating liner, the protective properties of the seal, for example with regard to permeability to moisture and radiation, can be precisely matched to the curable adhesive used. Instead of an adhesive tape with an exposed layer of the curable adhesive, a sealed adhesive tape is thus obtained directly, which is protected from external environmental influences and which can also be stored for a long period of time without a separate outer packaging or other separate protective measure, without premature, unwanted damage Curing of the curable adhesive comes.

The inventors have advantageously found that an appropriately sealed adhesive tape can be used particularly easily by the end user, since only the connection between the covering liner and the coating liner has to be severed in order to expose the curable adhesive composition in an optimal processing state.

It has been shown that advantages are also achieved in the subsequent application, in which the end user cuts off sections of the adhesive tape from a roll of appropriately sealed adhesive tape. This is because the surface area of the adhesive between the seals that is exposed by the cut is comparatively small, so that the deterioration in the application properties in this border area, based on the total adhesive in the adhesive tape, is negligible.

The objects mentioned above are thus achieved by a process for producing sealed adhesive tapes with curable adhesives and corresponding sealed adhesive tapes and uses of these sealed adhesive tapes, as defined in the claims. Preferred configurations according to the invention result from the dependent claims and the following statements.

Such features of methods according to the invention, which are referred to below as preferred, are combined in particularly preferred embodiments with other features referred to as preferred. Combinations of two or more of the processes described below as being particularly preferred are therefore very particularly preferred. Features of preferred sealed adhesive tapes according to the invention and their use result from the features of preferred methods according to the invention.

1. a) Herstellen oder Bereitstellen einer aushärtbaren Klebemasse,
2. b) Auftragen der aushärtbaren Klebemasse auf den Mittelabschnitt eines Beschichtungsliners, zum Erhalt eines abschnittsweise beschichteten Beschichtungsliners, der auf gegenüberliegenden Seiten des beschichteten Mittelabschnitts einen ersten und einen zweiten unbeschichteten Abschnitt aufweist,
3. c) Abdecken des abschnittsweise beschichteten Beschichtungsliners mit einem Abdeckliner zum Erhalt einer Schichtanordnung, bei der der Abdeckliner den beschichteten Mittelabschnitt des Beschichtungsliners vollständig sowie den ersten und zweiten unbeschichteten Abschnitt jeweils zumindest teilweise abdeckt, und
4. d) Verbinden des Abdeckliners mit dem Beschichtungsliner der Schichtanordnung im Bereich des ersten und des zweiten unbeschichteten Abschnitts, zum Erhalt eines versiegelten Klebebandes.

The invention relates to a method for producing sealed adhesive tapes with curable adhesives, comprising the steps:

1. a) producing or providing a curable adhesive composition,
2. b) application of the curable adhesive composition to the middle section of a coating liner to obtain a coating liner that is coated in sections and has a first and a second uncoated section on opposite sides of the coated middle section,
3. c) Covering the partially coated coating liner with a covering liner to obtain a layer arrangement in which the covering liner completely covers the coated central section of the coating liner and at least partially covers the first and second uncoated sections, and
4. d) Joining the cover liner to the coating liner of the layered arrangement in the area of the first and second uncoated sections to obtain a sealed adhesive tape.

In the context of the present invention, the term adhesive tape designates all thin, flat structures, ie structures with a predominant extension in two dimensions, in particular foils, Film sections and labels, preferably tapes of extended length and limited width, and corresponding tape sections.

In the method according to the invention, a curable adhesive is produced or provided in step a). This means that the curable adhesive can either be produced within the process or alternatively can only be made available, for example by the curable adhesive being purchased from a supplier.

Curable adhesives are known to those skilled in the art from the prior art. In the context of the present invention, the term curable adhesive refers to an adhesive that can be cured by an external stimulus by increasing the degree of crosslinking in the adhesive by a polymerization reaction, so that the average molecular weight of the polymeric components increases. The applicability of the method according to the invention is in principle not limited to specific curable adhesives, since the method according to the invention can also bring advantages for thermally curing curable adhesives, particularly with regard to clean and residue-free storage in the uncured state.

As explained above, however, the method according to the invention is particularly advantageous for those curable adhesives which have to be shielded from external environmental influences in order to retain their desired adhesive properties. The method according to the invention is therefore particularly advantageous for curable adhesives which contain highly volatile solvents and/or monomers and/or are moisture-curing and/or radiation-curing.

In practice, the process of the invention has proven to be particularly advantageous, particularly for the two last-mentioned curable adhesives. Accordingly, a method according to the invention is preferred, wherein the curable adhesive is a moisture-curing adhesive and/or a radiation-curing adhesive, wherein the curable adhesive is a moisture-curing adhesive.

Both radiation-curing and moisture-curing adhesives are known to those skilled in the art, for example from WO 2017 / 174 303 A1 , the EP 2 768 919 B1 or the U.S. 4,661,542 A .

Photoinitiators are present in radiation-curing adhesives, which are also referred to as radiation-crosslinking, which undergo decomposition under the influence of radiation and can thus start the polymerization. Examples of radiation-curing adhesives are known, in particular, from the field of epoxy adhesives or from the field of adhesives based on (meth)acrylates.

The method according to the invention is particularly well suited to keeping moisture away from the curable adhesive. Since, in practice, moisture-curing systems are particularly susceptible to premature, unwanted curing, the method according to the invention has proven to be particularly advantageous for these systems. A method according to the invention is therefore preferred in which the moisture-curing adhesive comprises a moisture-curing polyurethane adhesive and/or a moisture-curing silicone adhesive, the moisture-curing adhesive preferably being a moisture-curing silicone adhesive.

Among the moisture-curing adhesives known to those skilled in the art, some of which are also referred to as moisture-crosslinking, preference is given to polyurethane adhesives and, in particular, silicone adhesives. The silicone adhesives in particular have proven to be particularly suitable for the process of the invention in terms of their processing properties, it being possible in particular to achieve good detachability of the curable adhesive from the liners even without siliconizing the liners.

Even if, in principle, the use of multicomponent curable adhesives is possible, from the standpoint of processability, preference is given to a method according to the invention in which the curable adhesive is a one-component adhesive.

In step b) of the process of the invention, the curable adhesive is applied to a coating liner, suitable coating liners being known to those skilled in the art. This application does not take place over the entire surface of the coating liner, but only on a middle section of the coating liner. This middle section extends from the center of the coating line ners toward the side edges to form first and second uncoated sections on opposite sides of the coated center section.

In the context of the present invention, a first and a second uncoated section are involved if these sections are not covered by the curable adhesive. This does not rule out the possibility of the coating liner itself having a coating in the region of the first and second uncoated section, for example a plastic coating or partial siliconization, as long as this coating is not the curable adhesive. In this way a partially coated coating liner is obtained which has uncoated side edges surrounding the coated center section.

The coating liner that has been coated in sections is covered in step c) with what is known as a covering liner, so that a layered arrangement is created. The covering liner is placed in such a way that it completely covers the coated middle section of the coating liner and protrudes on the sides of the coated middle section in such a way that it also at least partially covers the first and second uncoated sections. Methods according to the invention are preferred here, with the covering liner completely covering the coated middle section of the coating liner and the first and second uncoated section in the layer arrangement.

The adhesive tape is sealed in step d) by connecting the cover liner to the coating liner, the connection taking place in the area of the first and second uncoated sections. This means that the sections of the coating liner and the covering liner that protrude beyond the coated central section are connected to one another, with the connection not being caused in particular by the curable adhesive composition. In this way a sealed adhesive tape is obtained.

In the context of the present invention, the term “sealed” means, in accordance with the understanding of the art, that the curable adhesive composition is at least partially shielded from external environmental influences in the interior of the bond between the covering liner and the coating liner.

However, especially for long tapes, the term “sealed” does not mean that the seal is complete or even hermetic. For production reasons, for example, only the longitudinal sides of a longer adhesive tape can be sealed by connecting the covering liner to the coating liner, so that an area remains at the beginning and end of the adhesive tape produced in the transverse direction in which the sealing is not complete. In view of the length of typical adhesive tapes and the diffusion of moisture in the sealed adhesive tape, this is usually acceptable from a manufacturing point of view. However, the cover liner and the coating liner are preferably connected to one another along the circumference of the coated center section over more than 98%, preferably 99%, particularly preferably 99.5% of the circumference of the coated center section.

In principle, it is possible to carry out the method according to the invention discontinuously and to produce separate adhesive tape units, for example in a rectangular shape, with small base areas of these separate adhesive tape units preferably producing a completely circumferential connection between the cover liner and the coating liner in order to shield the curable adhesive mass stored inside as best as possible . However, the particular advantages of the process according to the invention come into play in particular in continuous and semi-continuous processes. Long strands of adhesive tape can be produced here, which are sealed directly during production, i.e. "in-line", so to speak, before they are wound onto a roll of adhesive tape, for example.

This makes it possible to achieve a particularly high production output with the method according to the invention and at the same time to minimize the open time. The advantage of the method according to the invention is particularly evident here, since during the continuous production of the rear parts of the adhesive tape, the front parts of the adhesive tape that have already been wound up do not lose quality as a result of the environmental conditions, since they are sealed.

Thus, a process according to the invention is preferred which process is a continuous or a semi-continuous process, preferably a continuous process.

In this context, it has proven to be particularly advantageous to use the devices already available from conventional methods. To that extent is a method according to the invention preferably, the coating liner and/or the cover liner being provided as a rolled-up strip material, the coating liner and/or the cover liner preferably being provided continuously or semi-continuously via a feed arrangement, the feed arrangement preferably comprising at least one roll or roller through which the coating liner and/or the covering liner are unrolled and supplied to the process.

In the production of the sealed adhesive tape, it has been shown in practice that the layer arrangement and/or the sealed adhesive tape can easily become electrostatically charged, which can have a disadvantageous effect on the properties of the adhesive tape produced. In order to prevent this, metallic conductor rods are provided on the device used for production, which prevent electrostatic charging of the layer arrangement. Accordingly, a method according to the invention is preferred, wherein during the method electrostatic charging of the layer arrangement and/or the sealed adhesive tape is prevented by metallic conductor rods.

When designing the method according to the invention, it has proven to be particularly practicable to apply the adhesive to the coating liner through a nozzle. In this case, this nozzle can advantageously be connected directly to an extruder from which the curable adhesive composition is provided, it also being possible for the application to take place directly from an extruder without a nozzle. In order to ensure the best possible coverability of the coating liner coated in sections in step c) and to achieve a sealed adhesive tape that is as uniform as possible, it has proven advantageous to distribute the curable adhesive composition as uniformly as possible over the middle section of the coating liner.

In the light of these statements, preference is given to processes according to the invention in which the curable adhesive is applied in step b) via a nozzle and/or from an extruder. And also methods according to the invention, in which the curable adhesive composition, after application in step b), is distributed uniformly, preferably uniformly over the central section of the coating liner, preferably by a doctor blade or by a roller arrangement. It has proven to be particularly efficient here if the areal distribution is realized by a roller, which is also used to feed in the covering liner.

The method of the invention works particularly efficiently for comparatively small coating thicknesses of the curable adhesive. Depending on the later intended use of the adhesive tape, two thickness ranges in particular have proven to be particularly preferred, namely 50 to 2000 μm and 5500 to 7500 μm. Accordingly, a process according to the invention is preferred in which the curable adhesive composition in the coating liner, which has been coated in sections, has a thickness in the range from 50 to 8000 μm, preferably in the range from 50 to 2000 μm or in the + range from 5500 to 7500 μm, particularly preferably in the range from 100 to 1500 µm or in the range of 6000 to 7000 µm.

It has proven to be a particular advantage that the connection according to the invention in step d), i.e. the sealing of the two liners, is already possible if the coating liner and the cover liner only protrude slightly beyond the coated middle section, as long as it is possible connect protruding ends. This makes it possible, despite the sealing of the invention, to achieve very good surface utilization on the coating liner, so that the largest possible amount of curable adhesive can be applied to each meter of adhesive tape. Thus, a method according to the invention is preferred, wherein the coated middle section covers 80 to 99.5%, preferably 90 to 99%, particularly preferably 95 to 98%, of the surface of the coating liner coated in sections, the first and the second uncoated section preferably covering 0.25 each up to 10%, particularly preferably 0.5 to 5% each, of the surface area of the coating liner coated in sections, the first and the second uncoated section preferably having essentially the same size.

It has proven to be a particular advantage of the method according to the invention that, fortunately, just such materials can be used as the coating liner and/or covering liner which are already known as liners from the prior art and which can be processed correspondingly well as a thin and flexible layer material, as for example in the DE 10 2016 213 661 A1 are revealed. While certain liners such as thin glass and paper can be advantageous for selected applications, selected sealable plastics or paper or metal foils coated with such plastics or metal foils, for example aluminum foil coated with polyethylene, have been identified as particularly suitable because they are not only particularly water-impermeable, but also also independently sealable, so that the connection does not have to be made by a separate adhesive, for example, but can be made by welding.

A method according to the invention is correspondingly preferred, in which the coating liner and/or the cover liner consist of one or more materials selected from the list consisting of thin glass, paper, plastic, metal and laminates of these materials, preferably selected from the list consisting of Polyethylene vinyl alcohol, polyethylene naphthalate, polyethylene, polypropylene, cycloolefin copolymers, PVDC, polyvinylidene chloride and paper or metal foil coated with these plastics.

For certain applications, it has proven to be advantageous to at least partially siliconize the coating and/or the covering liner, cf. in this respect, for example DE 10 2016 213 661 A1 . This ensures that the coating liner and/or the covering liner can be detached from the curable adhesive as easily as possible, at least for many adhesives, although siliconization can also be disadvantageous when using moisture-curing silicone adhesives, since this leads to strong adhesion on the siliconized surface can lead, which is undesirable at least if none of the liners are to remain on the curable adhesive mass in subsequent use.

A complete siliconization of the surface of the liner is possible in principle, but not preferred, since the siliconization of the protruding side areas, i.e. the first and second uncoated sections, can affect the connectivity between the coating liner and the cover liner, for example because the adhesion of adhesive reduced or the weldability of two plastic layers is reduced. Correspondingly, it is preferred to provide a reduced surface coverage of the first and second uncoated sections in the case of siliconization of the side regions, so that a connection by welding, i. H. a seal is possible in this area or the adhesion of adhesives is increased in this area.

This means that a method according to the invention is preferred in which the coating liner and/or the cover liner are at least partially siliconized on the surface facing the curable adhesive composition, preferably exclusively in the area of the middle section, the siliconization preferably having a mass of 0.1 to 4 g/m ² , particularly preferably 0.3 to 3 g/m ² , preferably in a thickness in the range from 0.2 to 4 μm, particularly preferably in the range from 0.3 to 3 μm, with the coverage of the first and the second uncoated section through the layer produced by siliconization is particularly preferably in the range from 46 to 95%.

If a moisture-curing adhesive is used as the curable adhesive, it has proven to be particularly advantageous to form the coating and/or the cover liner, preferably both liners, from a material that has a particularly low water vapor permeability, since this increases the long-term durability of moisture-curing Adhesive masses can be particularly increased. In this respect, the inventors were able to identify particularly suitable limit values.

Accordingly, a method according to the invention is preferred, wherein the coating liner and / or the cover liner has a water vapor permeability WVTR measured according to ASTM F1249 - 01 of less than 5 g / m ² per day, preferably less than 3 g / m ² per day, particularly preferably less than 1.5 g/m ² per day.

For reasons of cost, it is usually most efficient to provide coating and covering liners in the method according to the invention that are only made in one piece. However, for certain applications it can be expedient to design one of the liners in two parts. For example, the coating liner could be formed from a wide lower layer and a narrower upper layer, with the upper layer forming the middle section in the method according to the invention, whereas the sides of the lower layer projecting beyond the upper layer form the first and second uncoated sections. In this case, in which the material of the upper and lower layer can be selected differently, for example, the sealing, ie the connection in step d), takes place between the lower layer of the coating liner and the covering liner, with the upper layer of the coating liner later Use of the adhesive tape can remain, for example, as a carrier material for the curable adhesive. It is thus possible with the adhesive tape obtained, for example, to remove only the covering liner and the lower layer of the coating liner before use in order to bond the curable adhesive composition applied to the upper layer of the coating liner together with the upper layer of the coating acting as a carrier to use tungsten liners. Accordingly, a method according to the invention is preferred, in which the coating liner or the covering liner is designed in two parts.

In cases in which the curable adhesive composition is radiation-curing, it has proven advantageous to design the liner to be radiation-impermeable, particularly in the wavelength range in which the photoinitiator provided in the liner is activated. This can be done, for example, by coloring plastic liners or using at least partially metallic liners. It has proven to be particularly useful to design the liner in such a way that the transmission measurement results in an absorption of more than 80%.

Accordingly, methods according to the invention are preferred, in which the coating liner and/or the cover liner has an absorption of more than 80 at a wavelength in the range from 200 to 900 nm, preferably in the range from 300 to 800 nm, particularly preferably in the range from 400 to 700 nm %, preferably more than 90%, particularly preferably more than 95%.

For later use of the adhesive tapes produced, the connection between the coating liner and the cover liner is broken. It has proven to be helpful for this if there are gripping aids on the outside of the liner that make it easier to tear open the seal. A method according to the invention is therefore preferred in which the coating liner and/or the cover liner have one or more gripping aids on the surface facing away from the curable adhesive.

The connection in step d) is of particular importance. It is preferred that this connection takes place in the method according to the invention in such a way that it is a permanent joint, with a substantially fluid-tight connection between the covering liner and the coating liner being formed in a targeted manner, particularly in the case of moisture-curing systems. This can be implemented particularly efficiently by means of a material connection between the cover liner and the coating liner.

Thus, a method according to the invention is preferred, wherein the connection in step d) is a permanent joining, so that the bond between the covering liner and the coating liner cannot be detached reversibly and non-destructively, and/or wherein the connection in step d) takes place in such a way that at least a fluid-tight, preferably water vapor-tight, connection between the covering liner and the coating liner is formed in sections, and/or wherein the connection in step d) takes place in such a way that at least in sections a material connection is formed between the covering liner and the coating liner.

Of the various joining methods that are suitable for connecting the covering liner to the coating liner, the use of an adhesive or a sealing lacquer is preferred for certain applications, since these methods have a high level of flexibility with regard to the material of the liner used. From the point of view of process technology, however, welding of the covering liner to the coating liner is preferred, which can take place if the liners are made of sealable material, in particular plastic, or have a corresponding coating. A method according to the invention is therefore preferred, in which the connection in step d) takes place by means of an adhesive and/or by means of a sealing lacquer and/or by welding the covering liner to the coating liner.

In the case of sealable materials, the covering liner is welded to the coating liner by applying pressure and/or thermal energy in the area to be joined. For the production of long strips of adhesive tape in the process according to the invention, the use of sealing tongs or sealing wheels has proven itself, which, through the application of pressure and/or thermal energy, causes the cover liner to be bonded to the coating liner in the area of the first and second uncoated sections to the side of the center section. The corresponding system has proven to be very efficient, so that large throughputs of adhesive tape to be sealed can also be realized with this system, with the simple design of the sealing device having proven to be particularly robust and error-resistant. Thus, a method according to the invention is preferred, wherein the connection in step d) takes place by welding the covering liner to the coating liner with one or more sealing tongs or with one or more sealing wheels, the welding in the case of continuous or semi-continuous processes preferably being carried out continuously or semi-continuously.

For some curable adhesives, it can be advantageous, with a view to the structure and also to the later adhesive performance, to first treat them before the final sealing, for example by supplying thermal energy or radiation. This can be the case, for example, if the degree of crosslinking of the curable adhesive at the time of application to the coating liner does not yet correspond to the degree of crosslinking that is intended for the later application, so that this must be specifically adjusted by the additional treatment step before the seal is created . A method according to the invention is therefore preferred in which the curable adhesive is thermally treated and/or irradiated after step b) and/or after step c), preferably in an oven.

A particularly interesting further development of the method according to the invention has proven to be the provision of a further device which can produce an additional connection area between the liners transversely to the web of the adhesive tape. In a corresponding method, during the course of adhesive tape production, additional seals are made at adjustable intervals perpendicular to the feed direction, so that a quilted adhesive tape is obtained which comprises a large number of individual compartments in each of which a subset of the curable adhesive composition is arranged. A corresponding adhesive tape has the advantage that it can be adapted to later customer requirements in that prefabricated lengths of adhesive strips are provided, which can be separated individually from a longer roll and used without the seal of the other compartments on the roll being broken got to. This has proven to be particularly advantageous with regard to the storage of corresponding adhesive tapes. Accordingly, a method according to the invention is preferred, wherein in the continuous or semi-continuous method after step d) an additional connection area of the covering liner with the coating liner is produced, preferably by sealing tongs, which runs perpendicular to the feed direction of the coating liner, so that a large number of interconnected, peripheral sealed tapes can be obtained.

It is a particular advantage of the method according to the invention that it does not generally require the use of a vacuum and/or a protective gas atmosphere, which is expensive in terms of apparatus, but counteracts a deterioration in the quality of the adhesive tape produced during the open time even without these means. Nevertheless, it is fundamentally possible to combine the advantages of the method according to the invention with a protective gas atmosphere, so that the exposure of the adhesive tape produced to atmospheric moisture is further minimized. This procedure has the synergistic effect that, instead of ambient air, part of the protective gas atmosphere is also enclosed in the seal, so that the moisture content of the air sealed in together with the curable adhesive is particularly low. Even if this process is significantly more complex than a process without a protective gas atmosphere, this preferred process according to the invention makes it possible to obtain particularly high-quality and durable sealed adhesive tapes.

Accordingly, a method according to the invention is preferred, one or more steps of the method being carried out under a protective gas atmosphere with a reduced moisture content, in particular a nitrogen or argon protective gas atmosphere.

As explained above, it is expedient for many later applications to provide the sealed adhesive tape in the form of a roll. The particular advantage of the method of the invention comes into play here that the lateral delimitation of the adhesive by the seal can also prevent unwanted escape of the adhesive on the sides of the adhesive tape when the adhesive tape is rolled up and the resulting pressure on the underlying layers. The method according to the invention is therefore particularly advantageous because it is particularly clean and precise.

• e) Aufrollen des versiegelten Klebebandes zum Erhalt einer Klebebandrolle, und optional den Schritt:
• f) Zerteilen der Klebebandrolle parallel zur Abrollrichtung, zum Erhalt von zwei oder mehreren kleinere Rollen, wobei vorzugsweise zumindest an einer Flanke der Rollen die Schnittkante mit einer Folie abgedeckt wird, die eine Wasserdampfdurchlässigkeit WVTR gemessen nach ASTM F1249 - 01 von weniger als 5 g/m² pro Tag, bevorzugt weniger als 3 g/m² pro Tag, besonders bevorzug weniger als 1,5 g/m² pro Tag, aufweist.

Depending on the width of the adhesive tape produced, it may be useful to subsequently divide the roll obtained into two or more smaller rolls parallel to the unwinding direction, ie perpendicular to the longitudinal direction of the roll. However, this disadvantageously results in a cut edge, which leads through the sealed composite and breaks it up accordingly, so that the curable adhesive composition comes into contact with the environment at this cut edge. To solve this problem, the inventors have provided that the cut edge can be covered with a foil on the flank of the roll that has been cut open, which foil prevents the ingress of moisture. In this respect, a method according to the invention is preferably additionally comprising the step:

• e) rolling up the sealed tape to obtain a roll of tape, and optionally the step:
• f) Cutting the roll of adhesive tape parallel to the direction of unwinding to obtain two or more smaller rolls, with the cut edge preferably being covered with a film at least on one flank of the rolls, which has a water vapor permeability WVTR measured according to ASTM F1249 - 01 of less than 5 g/ m ² per day, preferably less than 3 g/m ² per day, particularly preferably less than 1.5 g/m ² per day.

In the light of the above statements, it is obvious to the person skilled in the art that the present invention correspondingly also relates to a sealed adhesive tape and a corresponding roll of adhesive tape which comprises an adhesive tape according to the invention.

The invention thus relates to a sealed adhesive tape, preferably producible using the method according to the invention, comprising a curable adhesive mass arranged between a coating liner and a cover liner, the coating liner and the cover liner being bonded to one another on at least two sides of the curable adhesive mass and/or impermeable to water vapor.

The invention also relates to an adhesive tape roll comprising a rolled-up sealed adhesive tape according to the invention, the adhesive tape roll having a layer sequence of cover liner, coating liner, curable adhesive composition, cover liner and coating liner in the radial direction from the inside to the outside.

The use of a sealed adhesive tape according to the invention has proven to be particularly simple, and a reproducible quality of the joint can be obtained particularly reliably, since the sealed adhesive tape is protected from unwanted premature curing of the curable adhesive.

The sealed adhesive tape according to the invention is measured, for example, from a corresponding roll of adhesive tape and severed therefrom, for example using scissors. Before application, the composite of covering and coating liner is broken up. It is expedient here that initially only one of the liners is removed in order to ensure that the open adhesive tape obtained is as easy to handle as possible. The curable adhesive is now brought into the intended end position, for example applied to a component, after which the second liner can be removed. The second element to be connected is then placed accordingly. The adhesive is now cured, for example, by moisture crosslinking, either directly from atmospheric moisture or by the application of additional water, for example in the form of a spray mist. When separating a piece of sealed adhesive tape from a roll of adhesive tape, it has proven to be advantageous with a view to the long-term storage of the remaining roll if the cutting is not performed with scissors, but with a separating device that cuts the remainder of the adhesive tape across the tape roll to the direction of unwinding is sealed by connecting the cover liner to the coating liner, so that this resulting end piece is also protected from environmental influences. The invention thus relates to the use of a sealed adhesive tape according to the invention for joining two elements, the bond made up of cover liner and coating liner being broken open and the cover liner and/or the coating liner being removed from the curable adhesive composition.

A use according to the invention is preferred, with the joining taking place with a section of the sealed adhesive tape which was separated from an adhesive tape roll with an adhesive tape according to the invention, the separation preferably being effected by a separating device which cuts the remainder of the adhesive tape remaining on the adhesive tape roll transversely to the unwinding direction sealed by bonding the cover liner to the coating liner.

In order to visualize the problem of the deterioration of the adhesive performance with longer open times, the inventors for a moisture-curing adhesive, which was a typical silicone adhesive, used a time-dependent compression relaxation measurement to determine the dependence of the relaxation, which is a measure of the degree of crosslinking in the curable adhesive mass is determined by the open time in normal climate. The results are shown in Table 1 below. Table 1: open time / min relaxation / % 0 91.2 5 91.1 10 90.3 15 90.1 20 90.0 25 88.0 10000 45.0

It is clearly evident that the relaxation has already fallen to 88% after 25 minutes, which means that the degree of crosslinking increases after a short open time under normal climate and a quick exclusion of moisture is essential.

• 1 eine schematische Seitenansicht des erfindungsgemäßen Verfahrens in einer ersten bevorzugten Ausgestaltung;
• 2 eine schematische Draufsicht des erfindungsgemäßen Verfahrens in der ersten bevorzugten Ausgestaltung;
• 3 eine schematische Seitenansicht des erfindungsgemäßen Verfahrens in einer zweiten bevorzugten Ausgestaltung.

Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings. show:

• 1 a schematic side view of the method according to the invention in a first preferred embodiment;
• 2 a schematic plan view of the method according to the invention in the first preferred embodiment;
• 3 a schematic side view of the method according to the invention in a second preferred embodiment.

1 visualizes the method according to the invention by a schematic representation of the method according to the invention in a first preferred embodiment. For this shows 1 an abstracted snapshot of the operation of an apparatus for the continuous production of a sealed adhesive tape 10 with the method according to the invention, in which the steps of the method according to the invention can be seen.

In 1 It can be seen that a curable adhesive composition 12 is provided and applied to the central portion of a coating liner 14 , the coating liner 12 being continuously provided from a coiled strip material via a roller 22 . In this case, the coating is carried out in such a way that a first and a second uncoated section 16a, 16b remain free to the left and right of the coated central section of the coating liner 12 in the feed direction.

A cover liner 18 is continuously supplied via a second roller 22 in such a way that the coating liner 14 that has been coated in sections is completely covered, the coating liner 14 and the cover liner 18 having the same dimensions in the embodiment shown.

The layer arrangement 20 produced in this way, consisting of coating liner 14, curable adhesive 12 and cover liner 18, then runs through continuous sealing tongs 24, with the aid of which the coating liner 14 and the cover liner 18 are connected to one another on the side of the curable adhesive 12 by the application of pressure and heat. so that behind the continuous sealing tongs 24 the sealed adhesive tape 10 is obtained.

In accordance with the design 1 the curable adhesive 12 is a moisture-curing silicone adhesive. In the embodiment shown, this moisture-curing silicone adhesive is provided directly from an extruder (not shown) via a nozzle. Due to the contact pressure of the roller 22 conveying the cover liner 18, the curable adhesive is distributed evenly over the entire area. In this example, the gap between the rollers 22 is selected such that the curable adhesive 12 has a thickness of approximately 6000 μm and the coated middle section covers approximately 97.2% of the surface of the coating liner 14 which has been coated in sections.

Both the coating liner 14 and the cover liner 18 are made of polyethylene in the example shown in FIG. 1, are not siliconized and each have a thickness of approximately 100 μm. The continuous sealing tongs 24 create a permanent, fluid-tight and cohesive bond between the coating liner 14 and the cover liner 18, which cannot be detached reversibly and non-destructively.

The sealed adhesive tape 10 produced is wound onto an adhesive tape roll (not shown) immediately behind the continuous sealing tongs 24, so that a layer sequence of cover liner 18, coating liner 14, curable adhesive composition 12, cover liner 18 and coating liner is present on the roll in the radial direction from the inside to the outside 14 is obtained.

The resulting sealed tape 10 can be measured and severed from the roll of tape for later use. For the application, the composite of coating liner 14 and cover liner 18 must be broken, after which the curable adhesive 12 can be arranged in the desired position and then cured.

2 shows a schematic plan view of the in 1 methods shown or to the in 1 device shown, only the rear portion of the device in the area of the continuous sealing tongs 24 being shown. For reasons of clarity, the width of the adhesive tape was reduced in the illustration. On an actual scale, the width of the first and second uncoated section 16a, 16b is only 20 mm each, based on a total width of 1400 mm, and the coated central section is therefore approximately 97.2% occupied.

In 2 the areas in front of and behind the continuous sealing tongs 24 are identified in which the layer arrangement 20 or the sealed adhesive tape 10 is still present. The feed direction is indicated by an arrow. In 2 It can be seen that the continuous sealing tongs 24 arranged on both sides leave behind a weld seam in the region of the first and second uncoated sections 16a, 16b, through which the connection between the coating liner 14 and the covering liner 18 is realized.

In 2 the cover liner 18 is partially hidden in the upper area in order to allow a view of the underlying layers of the curable adhesive composition 12 and the coating liner 14 .

3 shows a second embodiment of the method according to the invention, which differs from that in 1 shown differs in particular in that the covering liner 18 is not supplied at the same time as the coating liner 14 . Instead, initially only the coating liner 14 is coated with the curable adhesive 12 and rolled out by a roller 22 as before. The two-layer assembly is then passed through an oven 26 and is thermally treated therein. After passing through the oven 26, the cover liner 18 is applied to thereby produce the sandwich 20, which is then converted by the continuous sealing tongs 24 into the sealed adhesive tape 10 of the present invention.

The invention is also explained in more detail below using exemplary embodiments.

• In einem Rührer wurden unter Ausschluss von Luftfeuchtigkeit die in Tabelle 2 aufgeführten Komponenten in den dort angegebenen Anteilen gemischt. Hierzu wurden zunächst das Polymer, d.h. das beidseitig hydroxyterminierte Polydimethylsiloxan, und die Pigmentpaste vorgelegt. Die Mischung wurde langsam auf 45 - 55 °C erwärmt und der Mischraum evakuiert. Unter Schutzgas wurden dann Methyltri(methylethylketoxim)silan, Tetraethylorthosilikat und Aminopropyltriethoxysilan zugegeben und eingemischt. Anschließend wurde unter Schutzgas Vinyltri(methylethylketoxim)silan zugegeben. Im nächsten Schritt wurden die Kreiden portionsweise unter Schutzgas zugegeben. Im letzten Schritt wurde Dibutylzinndilaurat unter Schutzgas eingemischt.

Tabelle 2: Zusammensetzung der Mischung zur Herstellung der aushärtbaren Silikon-Klebemasse Beidseitig hydroxyterminiertes Polydimethylsiloxan (PDMS) (Mw = 100.000 g/mol, η = 80 Pa·s) 31,62 Gew.-% Methyltri(methylethylketoxim)silan 2,91 Gew.-% Tetraethylorthosilikat 0,45 Gew.-% Vinyltri(methylethylketoxim)silan 1,04 Gew.-% Aminopropyltriethoxysilan 1,29 Gew.-% Pigmentpaste (Ruß dispergiert in PDMS-Öl, Wacker ELASTOSIL Farbpaste 9005 schwarz) 5,25 Gew.-% unbehandelte Kreide 44,67 Gew.-% mit Fettsäure behandelte Kreide 12,76 Gew.-% Dibutylzinndilaurat 0,01 Gew.-% Production of a curable silicone adhesive:

• The components listed in Table 2 were mixed in the proportions stated there in a stirrer with exclusion of atmospheric moisture. For this purpose, the polymer, ie the polydimethylsiloxane which is hydroxy-terminated on both sides, and the pigment paste were initially introduced. The mixture was slowly heated to 45-55°C and the mixing space was evacuated. Methyltri(methylethylketoxime)silane, tetraethylorthosilicate and aminopropyltriethoxysilane were then added and mixed in under a protective gas. Vinyltri(methylethylketoxime)silane was then added under a protective gas. In the next step, the chalks were added in portions under protective gas. In the last step, dibutyltin dilaurate was mixed in under an inert gas.

Table 2: Composition of the mixture for producing the curable silicone adhesive Double-hydroxy-terminated polydimethylsiloxane (PDMS) (Mw = 100,000 g/mol, η = 80 Pa s) 31.62% by weight methyltri(methylethylketoxime)silane 2.91% by weight tetraethylorthosilicate 0.45% by weight vinyltri(methyl ethyl ketoxime)silane 1.04% by weight aminopropyltriethoxysilane 1.29% by weight Pigment paste (soot dispersed in PDMS oil, Wacker ELASTOSIL color paste 9005 black) 5.25% by weight untreated chalk 44.67% by weight Chalk treated with fatty acid 12.76% by weight dibutyltin dilaurate 0.01% by weight

The mixture M1 produced in this way was mixed with a PDMS hydroxy-terminated on both sides (Mw=70,000 g/mol, η=20 Pa·s) in a weight ratio M1:PDMS of 7.5:1, further excluding atmospheric moisture.

• Nach 6 Stunden wurde die erhaltene feuchtigkeitshärtende Silikon-Klebemasse in zwei Verfahren zur Herstellung von Klebebändern jeweils mittels einer Düse auf den Mittelabschnitt einer HDPE-Folie (Infiana, Qualität 74325, 75 µm, weiß) aufgetragen und zwischen zwei Walzen zu einer Bahn mit einer Schichtdicke von 1.000 µm und einer Breite von 500 mm ausgeformt, wobei der derart gebildete, abschnittsweise beschichtete Beschichtungsliner über eine der Walzen simultan mit der Ausformung der Massenbahn zudem mit einem Abdeckliner aus HDPE-Folie abgedeckt wurde (Beschichtungsgeschwindigkeit: 3 m/min).

Production of adhesive tapes:

• After 6 hours, the moisture-curing silicone adhesive mass obtained was applied in two processes for the production of adhesive tapes, each by means of a nozzle to the middle section of an HDPE film (Infiana, quality 74325, 75 μm, white) and applied between two rollers to form a web with one layer thickness of 1,000 µm and a width of 500 mm, the coating liner formed in this way being coated in sections was also covered with a covering liner made of HDPE film via one of the rollers simultaneously with the shaping of the mass web (coating speed: 3 m/min).

• Beide Linerfolien wiesen in Vorschubrichtung links und rechts jeweils einen für derartige Beschichtungen üblichen durchgehenden Überstand (nicht mit der Klebmasse in Kontakt befindlichen Bereich) von 1 cm auf.

Comparative example:

• In the feed direction, both liner films had a continuous overhang (area not in contact with the adhesive) of 1 cm on the left and right, which is typical for coatings of this type.

In this comparative example, the two liner sheets were not joined in the area of the overhang, i.e. the first and the second uncoated section. The mass web thus obtained, covered on the upper and lower sides with liner films, was instead wound up into a roll, which was welded into a film (Boss® Vacuum Moisture Barrier Bag Dryshield 150) after a web length of 1,000 linear meters (linear meters) had been reached.

• Beide Linerfolien wiesen in Vorschubrichtung links und rechts jeweils einen durchgehenden Überstand (nicht mit der Klebmasse in Kontakt befindlichen Bereich) von 2,5 cm auf.

Example according to the invention:

• Both liner films had a continuous overhang (area not in contact with the adhesive) of 2.5 cm on the left and right in the feed direction.

Immediately after its production, the compound consisting of the ground sheet and the liner foils applied to the top and bottom passed through two continuous sealing wheels, with which the liner areas protruding left and right in the feed direction were thermally welded together. The product obtained in this way was wound up into a roll, the final web length was 1,000 linear meters.

• Aluminiumprofile (Prüfkörper Alu 6060 E6EV1, 76 × 25 × 5 mm) wurden mit Isopropanol gereinigt, woraufhin das Lösemittel 10 min abdampfen konnte. Die Klebmassebahnen wurden entrollt und vom Linermaterial befreit; anschließend wurden zügig aus 10 gleichmäßig über die volle Länge der Bahn verteilten Abschnitten rechteckige Proben mit einer Kantenlänge von 12,5 × 50 mm zugeschnitten.

Forehead pull test:

• Aluminum profiles (test specimen Alu 6060 E6EV1, 76×25×5 mm) were cleaned with isopropanol, after which the solvent was allowed to evaporate for 10 minutes. The webs of adhesive were unrolled and freed from the liner material; Rectangular samples with an edge length of 12.5×50 mm were then quickly cut from 10 sections evenly distributed over the full length of the web.

Two aluminum profiles each were bonded to a sample and loaded with 3 kg for 10 s. The test piece produced in this way was then stored for two weeks at 23° C. and 50% relative humidity. The test specimen was then clamped into a ZWICK tensile testing machine, whereupon the two aluminum blocks were pulled apart at a speed of 12.7 mm/min. The maximum force required for this was measured, and Table 3 gives the mean value of two individual measurements in kPa as the result. Table 3: Forehead pull test results Measuring section / running meters from the beginning of the coating (total bale 1000 Ifm, coating speed 3 m/min) Minutes from start of coating to sealing (only for the comparative example) Maximum forces comparative example (kPa) Maximum forces according to the example (kPa) 1,000 < 1 519 522 985 5 502 515 970 10 495 527 955 15 475 519 910 30 407 530 820 60 312 529 640 120 298 510 100 300 280 512

From the results summarized in Table 3, the advantages of the method according to the invention and the adhesive tape according to the invention are immediately apparent to the person skilled in the art. In the comparative example, the maximum forces, which can serve as an indicator of the quality of the adhesive tape obtained, decrease continuously the longer the respective sections were exposed to the ambient air from the start of coating until sealing. This corresponds to a decreasing adhesive performance. In clear contrast to this, with the sealed adhesive tape obtained using the method according to the invention, almost constant adhesive performance is achieved over the entire length of the adhesive tape, which is expressed in only minimal differences between the maximum forces determined.

Reference List

10

Sealed tape

12

Curable adhesive mass

14

coating liner

16a

first uncoated section

16b

second uncoated section

18

cover liner

20

layer arrangement

22

roller

24

sealing tongs

26

oven

Claims (10)

Method for producing sealed adhesive tapes (10) with curable adhesives (12), comprising the steps: a) producing or providing a curable adhesive (12), b) applying the curable adhesive (12) to the middle section of a coating liner (14), to obtain a partially coated coating liner (14) having a first and a second uncoated portion (16a, 16b) on opposite sides of the coated center portion, c) covering the partially coated coating liner (14) with a cover liner (18) to obtain a Layer arrangement (20), in which the cover liner (18) completely covers the coated middle section of the coating liner (14) and at least partially covers the first and second uncoated sections (16a, 16b), and d) joining the covering liner (18) to the coating liner (14) of the layer arrangement (18) in the region of the first and second uncoated sections (16a, 16b) to obtain a sealed adhesive tape (10). procedure after claim 1 , wherein the curable adhesive (12) is a moisture-curing adhesive and / or a radiation-curing adhesive, wherein the curable adhesive (12) is preferably a moisture-curing adhesive. procedure after claim 2 , wherein the moisture-curing adhesive comprises a moisture-curing polyurethane adhesive and / or a moisture-curing silicone adhesive, wherein the moisture-curing adhesive is preferably a moisture-curing silicone adhesive. Procedure according to one of Claims 1 until 3 , wherein the process is a continuous or a semi-continuous process, preferably a continuous process. Procedure according to one of Claims 1 until 4 , wherein the coated central section covers 80 to 99.5%, preferably 90 to 99%, particularly preferably 95 to 98%, of the surface of the coating liner (14) coated in sections, with the first and second uncoated sections (16a, 16b) being preferred each make up 0.25 to 10%, particularly preferably 0.5 to 5% of the surface of the coating liner (14) coated in sections, the first and the second uncoated section (16a, 16b) preferably having the same size. Procedure according to one of Claims 1 until 5 , The coating liner (14) and/or the cover liner (18) having a water vapor permeability WVTR measured according to ASTM F1249-01 of less than 5 g/m ² per day, preferably less than 3 g/m ² per day, particularly preferably less than 1.5 g/m ² per day. Procedure according to one of Claims 1 until 6 , wherein the coating liner (14) and / or the covering liner (18) at a wavelength in the range from 200 to 900 nm, preferably in the range from 300 to 800 nm, particularly preferably in the range from 400 to 700 nm, an absorption of more than 80%, preferably more than 90%, particularly preferably more than 95%. Procedure according to one of Claims 1 until 7 , wherein the connection in step d) takes place by means of an adhesive and/or by means of a sealing lacquer and/or by welding the covering liner (18) to the coating liner (14), preferably by welding. Sealed adhesive tape (10), producible with a method according to one of Claims 1 until 8th , comprising a curable adhesive composition (12) arranged between a coating liner (14) and a covering liner (18), the coating liner (14) and the covering liner (18) being cohesively bonded and/or impermeable to water vapor on at least two sides of the curable adhesive composition (12). are connected. Using a sealed tape (10) after claim 9 for joining two elements, the composite of cover liner (18) and coating liner (14) being broken up and the cover liner (18) and/or the coating liner (14) being removed from the curable adhesive (12).

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